Mutation rate of 7 X-STRs of common use in population genetics

microsatellite loci analysis is a relevant tool in population genetic studies and also in paternity testing. in this field the x-chromosome str loci are widely used for female offspring testing but their mutation rates are scarcely known. in this work we performed a mutation rate analysis of seven str markers located in the x- chromosome specific region, in mother-son pairs and father-mother-daughter trios. among 1015 allele transfers, we found only one change for a mother-daughter transmission in the dxs9898 locus, consisting of a loss of one single repeat. this finding allowed us to estimate a general mutation rate of μ=9.85 x 10-4 (2.49 x 10-4 - 5.49 x 10-2) which can be applied to population studies. this value is consistent with other reports on autosomal str loci, suggesting that similar molecular mechanisms are acting on x and autosomal repetitive markers.